Impact of Contracted Endodontic Access Cavity Designs on Root Canal Disinfection Using Diode Laser: An in-Vitro Study

Abstract Introduction: New approaches for minimal invasive endodontic access cavity designs had been introduced for preserving the structural integrity of the offending tooth. Diode laser has been now widely used in root canal disinfection and showing highly promising results. Aim: to evaluate the impact of contracted endodontic access cavity designs on root canal disinfection using diode laser. Materials and Methods: Fifty-four intact freshly extracted human mandibular first molars were selected for the use in this study. Only the mesial roots of the selected samples were included in this study. Samples were randomly divided into three equal groups (n=18) according to the type of access cavity performed. Group (1): conventional access cavities, Group (2): Ninja access cavities, and Group (3): truss access cavities. Isolates of Enterococcus Faecalis (E.Fecacalis) were introduced in the root canals of the mesial roots of the selected samples. Samples were further sub-divided into two equal sub-groups (n=9) according to the disinfection method. Sub-group (a): Diode laser disinfection, and Sub-group (b): NaOCl 2.5% followed by EDTA 17% irrigation. Bacterial evaluation was performed using confocal laser scanning electron microscope. Results: The results showed that using Diode laser disinfection have shown higher bacterial reduction in comparison to NaOCl irrigation, but with no statistically significant difference. For access cavity designs, regardless of the type of disinfection used, conventional access cavities have shown the highest bacterial reduction, with the least bacterial reduction with Ninja access cavities. Conclusion: Contracted endodontic access cavities did not offer any advantages in comparison with the conventional endodontic access cavities regarding bacterial reduction. Diode laser can be used as an effective adjunct tool in root canal disinfection

Fault-Tolerant Operation of Delta-Connected Scalar- and Vector-Controlled AC Motor Drives

Operation and analysis of delta-connected ac motor-drive systems under fault-tolerant open-phase mode of operation is introduced in this paper for both scalar- and vector-controlled motor-drive systems. This technique enables the operation of the three-phase motor upon a failure in one of its phases without the need of a special fault-detection algorithm. It is mainly used to significantly mitigate torque pulsations, which are caused by an open-delta configuration in the stator windings. The performance of the fault-tolerant system was verified using a detailed time stepping finite element simulation as well experimental tests for a 5-hp 460-V induction motor-drive system and the results are presented in this paper This paper also compares the operation of this fault-tolerant mode of operation for the cases of scalar-controlled and closed-loop vector-controlled motor-drive systems

An Efficient Certificateless Encryption for Secure Data Sharing in Public Clouds

We propose a mediated certificateless encryption scheme without pairing operations for securely sharing sensitive information in public clouds. Mediated certificateless public key encryption (mCL-PKE) solves the key escrow problem in identity based encryption and certificate revocation problem in public key cryptography. However, existing mCL-PKE schemes are either inefficient because of the use of expensive pairing operations or vulnerable against partial decryption attacks. In order to address the performance and security issues, in this paper, we first propose a mCL-PKE scheme without using pairing operations. We apply our mCL-PKE scheme to construct a practical solution to the problem of sharing sensitive information in public clouds. The cloud is employed as a secure storage as well as a key generation center. In our system, the data owner encrypts the sensitive data using the cloud generated users’ public keys based on its access control policies and uploads the encrypted data to the cloud. Upon successful authorization, the cloud partially decrypts the encrypted data for the users. The users subsequently fully decrypt the partially decrypted data using their private keys. The confidentiality of the content and the keys is preserved with respect to the cloud, because the cloud cannot fully decrypt the information. We also propose an extension to the above approach to improve the efficiency of encryption at the data owner. We implement our mCL-PKE scheme and the overall cloud based system, and evaluate its security and performance. Our results show that our schemes are efficient and practical

Fault-Tolerant Technique for Δ-Connected AC-Motor Drives

A fault-tolerant technique for motor-drive systems is introduced in this paper. The technique is merely presented for ac motors with Δ-connected circuits in their stator windings. In this technique, the faulty phase is isolated by solid-state switches after the occurrence of a failure in one of the stator phases. Then, the fault-tolerant technique manages current-flow in the remaining healthy phases. This technique is to significantly mitigate torque pulsations, which are caused by an open-Δ configuration in the stator windings. The performance of the fault-tolerant technique was experimentally verified using a 5-hp 460-V induction motor-drive system and the results are presented in this paper

Effect Of Qualitative Exercises Using The (Vertimax) Device To Developing The Explosive Ability Of Arms And Legs And The Skill Of Long-Shooting For Youth In Handball

The importance of the research was to prepare qualitative exercises using the device (Vertimax) to develop the explosive ability of the arms and legs and the skill of long- shooting for young handball players. As well as knowing the effect of specific exercises using the device (Vertimax) to develop the explosive ability of the arms and legs and the skill of long-range shooting for young handball players. While the problem of the research was that there was a weakness in the explosive ability and the far shooting, so the player needs a high level of the explosive ability of the arms and legs in order to succeed the far shooting. Therefore, the researchers decided to develop specific exercises using the (Vertimax) device to develop the explosive ability of the arms and legs and the skill of long-range shooting for young handball players. As for the objectives of the research, it was to prepare qualitative exercises using the (Vertimax) device to develop the explosive ability of the arms and legs and the skill of long-range shooting for young players in handball. As well as knowing the effect of these specific exercises to develop the explosive ability of the arms and legs and the skill of long-range shooting for young handball players. As for the most important conclusions, it was represented that the specific exercises used on the device (Vertimax) have a positive effect on the development of the explosive power of the arms and legs and the skill of long-range shooting for young handball players. Therefore, the researchers recommend the need to use specific exercises using the (Vertimax) device to develop the explosive power of the arms and legs and the skill of long-range shooting for young players in handball

Short- and Long-term Effectiveness of Sacral Nerve Stimulation in Patients with Overactive Bladder

BACKGROUND: Sacral nerve stimulation (SNS) approved for use in North America since 1997 despite the fact that the concept of using SNS to treat patients with voiding dysfunction discussed first almost 50 years ago. AIM: The objectives of the study were to assess the effectiveness of SNS the short and long term for patients with overactive bladder (OAB) dysfunction and its relation to age, gender, and causes. PATIENTS AND METHODS: This is a clinical prospective study that involved 50 cases (32 females and 18 males) with OAB. It was carried out at Ibn Sina Hospital, and the neurosciences hospital in Baghdad/Iraq from April 2015 to April 2018. All the patients were assessed preoperatively and certain inclusion criteria were used. The patients went through the 2 stage implantations of the Medtronic InterStim®. The patients were assessed at 6 months (short term) and 2 years (long term) postoperatively. RESULTS: The results of our patients were analyzed with respect to age, gender, causes of OAB, and post-operative complications. We found that younger age patients, female patients, and patients with neurogenic causes of OAB showed a better response in both the short- and long-term follow-up. CONCLUSION: Considerable progress has been made in the surgical management of OAB. Proper selection of patients is the key to the success of SNS, and female patients have better results compared to male patients. Furthermore, younger patients and patients with neurogenic causes did better than older patients and patients with idiopathic causes. SNS is a safe minimally invasive surgery with a low complication rate, and the 2 stages procedure has better results than the percutaneous nerve evaluation

Analysis and Diagnostics of Adjacent and Nonadjacent Broken-Rotor-Bar Faults in Squirrel-Cage Induction Machines

In this paper, faults associated with the rotor of an induction machine are considered. More specifically, effects of adjacent and nonadjacent bar breakages on rotor fault diagnostics in squirrel-cage induction machines are studied. It is shown that some nonadjacent bar breakages may result in the masking of the commonly used fault indices and, hence, may lead to a possible misdiagnosis of the machine. A discussion of the possible scenarios of these breakages as well as some conclusions regarding the types of squirrel-cage induction machines (number of poles, number of squirrel-cage bars, etc.) that may be more prone to these nonadjacent types of failures are presented. This discussion is supported through both simulation and experimental results. It is also shown that secondary fault effects can be used to diagnose such nonadjacent bar breakages